<!DOCTYPE html>
<html>
<head>
    <title>Custom element in MathML namespace</title>
    <link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
</head>
<body>
    <math xmlns="http://www.w3.org/1998/Math/MathML">
        <x-math-element id="x-math-element"></x-math-element>
    </math>
</body>
</html>
